This invention applies generally to the field of devices adapted to spray or coat the inner surfaces of a pipe or other member, primarily for the rehabilitation and/or lining of pipes or other tubular members wherein a polymer resin or similar uncured polymer material is sprayed onto the interior wall of the pipe, the sprayed material curing to form a layer possessing desirable properties, such as liquid impermeability, elasticity, rigidity, corrosion resistance, etc. The lining layer may be applied directly to the pipe wall itself, or successive layers may be applied to create multiple layers. The invention relates to such devices which comprise a spraying apparatus that is transported along the interior of the pipe, the sprayer apparatus typically comprising a spinner assembly with a rotating spinner member that receives and distributes the uncured polymer circumferentially as it moves linearly along the pipe, the spinner assembly being mounted onto a transport unit, either self-propelled or towed, that contacts the pipe surface during the operation. More particularly, the invention relates to structures adapted for maintaining the spinner member in the optimum centerline position within the pipe.
Fluid conveyance systems rely on the structural integrity of the pipe to safely and efficiently operate. In the municipal and industrial sectors, there are pipe systems that are degrading such that they fall below standards due to corrosion or crack propagation. These systems include for example the potable water transmission lines to residential areas which can range in sizes of 6 to 48 inches and will typically have complex networks that were installed and modified over many years as the neighborhoods were developed.
There are currently only a few methods to rehabilitate a pipe system to full structural integrity without excavating and replacing pipe segments. The current methods include Cast-In-Place-Pipe (CIPP) and Spray-In-Place-Pipe (SIPP). In the current SIPP methods, a SIPP spraying apparatus traverses the pipe by being pulled by an electrical and resin-supplying tether, known as the umbilical, or through robotic armatures. The spraying apparatus comprises a spinner member that ejects the lining material, such as an uncured or partially cured polymer resin, onto the inner diameter of the pipe, effectively creating a new pipe with a known thickness and structural properties inside the pre-existing pipe. In current systems, the location of the spinner member relative to the centerline of the pipe is determined solely by the geometry of the device, as the spinner assembly is mounted in fixed manner on the spraying apparatus. Having the spinner member coaxially aligned in the center of the pipe is imperative to achieving an even distribution of the lining material, which will guarantee the integrity of the lining process.
There are inherent flaws in relying on the device geometry of the spraying apparatus to center the spinner member. These flaws are the result of obstacles that the device can encounter within nearly every pipe system. The obstacles can include bends, rough terrain (due to joint misalignment or internal weld seams), potential change of pitch at joint, and/or the reaction of the umbilical on the device when extended over long distances (potential for rolling the device due to a torsion on the umbilical). Each of these obstacles will move the centerline of the spinner member off of the centerline of the pipe. This offset can be quite dramatic while transport through a pipe bend and will result in an unknown error of lining thickness in that area, which ultimately yields an unacceptable and potentially unclassifiable final product.
The main objective of this invention is to provide a spraying apparatus, device or assembly adapted to reposition the spinner assembly of the spraying apparatus such that the spinner assembly remains centered within the pipe throughout the lining process, thereby obviating the negative effect of bends and obstacles on lining thickness and consistency. This and other objects are addressed by providing a spraying apparatus with an articulating neck mount and multiple positioning assemblies, the mount adapted to alter the location of the spinner member so as to maintain the spinner member centered within the pipe.